[PATCH v2] usb: host: xhci: mvebu: make USB 3.0 PHY optional for Armada 3720

From: Pali Rohár
Date: Mon Feb 01 2021 - 10:09:49 EST


Older ATF does not provide SMC call for USB 3.0 phy power on functionality
and therefore initialization of xhci-hcd is failing when older version of
ATF is used. In this case phy_power_on() function returns -EOPNOTSUPP.

[ 3.108467] mvebu-a3700-comphy d0018300.phy: unsupported SMC call, try updating your firmware
[ 3.117250] phy phy-d0018300.phy.0: phy poweron failed --> -95
[ 3.123465] xhci-hcd: probe of d0058000.usb failed with error -95

This patch introduces a new plat_setup callback for xhci platform drivers
which is called prior calling usb_add_hcd() function. This function at its
beginning skips PHY init if hcd->skip_phy_initialization is set.

Current init_quirk callback for xhci platform drivers is called from
xhci_plat_setup() function which is called after chip reset completes.
It happens in the middle of the usb_add_hcd() function and therefore this
callback cannot be used for setting if PHY init should be skipped or not.

For Armada 3720 this patch introduce a new xhci_mvebu_a3700_plat_setup()
function configured as a xhci platform plat_setup callback. This new
function calls phy_power_on() and in case it returns -EOPNOTSUPP then
XHCI_SKIP_PHY_INIT quirk is set to instruct xhci-plat to skip PHY
initialization.

This patch fixes above failure by ignoring 'not supported' error in
xhci-hcd driver. In this case it is expected that phy is already power on.

It fixes initialization of xhci-hcd on Espressobin boards where is older
Marvell's Arm Trusted Firmware without SMC call for USB 3.0 phy power.

This is regression introduced in commit bd3d25b07342 ("arm64: dts: marvell:
armada-37xx: link USB hosts with their PHYs") where USB 3.0 phy was defined
and therefore xhci-hcd on Espressobin with older ATF started failing.

Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
Tested-by: Tomasz Maciej Nowak <tmn505@xxxxxxxxx>
Fixes: bd3d25b07342 ("arm64: dts: marvell: armada-37xx: link USB hosts with their PHYs")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.1+: ea17a0f153af: phy: marvell: comphy: Convert internal SMCC firmware return codes to errno
Cc: <stable@xxxxxxxxxxxxxxx> # 5.1+: f768e718911e: usb: host: xhci-plat: add priv quirk for skip PHY initialization

---
Changes in v2:
* Drop dependency on patch "usb: host: xhci-plat: fix support for XHCI_SKIP_PHY_INIT quirk"
* Introduce a new .plat_setup callback for xhci-plat drivers in this patch (to simplify backporting and review)
* Move implementation from xhci_mvebu_mbus_init_quirk() into xhci_mvebu_a3700_plat_setup()
---
drivers/usb/host/xhci-mvebu.c | 42 +++++++++++++++++++++++++++++++++++
drivers/usb/host/xhci-mvebu.h | 6 +++++
drivers/usb/host/xhci-plat.c | 20 ++++++++++++++++-
drivers/usb/host/xhci-plat.h | 1 +
4 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-mvebu.c b/drivers/usb/host/xhci-mvebu.c
index 60651a50770f..8ca1a235d164 100644
--- a/drivers/usb/host/xhci-mvebu.c
+++ b/drivers/usb/host/xhci-mvebu.c
@@ -8,6 +8,7 @@
#include <linux/mbus.h>
#include <linux/of.h>
#include <linux/platform_device.h>
+#include <linux/phy/phy.h>

#include <linux/usb.h>
#include <linux/usb/hcd.h>
@@ -74,6 +75,47 @@ int xhci_mvebu_mbus_init_quirk(struct usb_hcd *hcd)
return 0;
}

+int xhci_mvebu_a3700_plat_setup(struct usb_hcd *hcd)
+{
+ struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+ struct device *dev = hcd->self.controller;
+ struct phy *phy;
+ int ret;
+
+ /* Old bindings miss the PHY handle */
+ phy = of_phy_get(dev->of_node, "usb3-phy");
+ if (IS_ERR(phy) && PTR_ERR(phy) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ else if (IS_ERR(phy))
+ goto phy_out;
+
+ ret = phy_init(phy);
+ if (ret)
+ goto phy_put;
+
+ ret = phy_set_mode(phy, PHY_MODE_USB_HOST_SS);
+ if (ret)
+ goto phy_exit;
+
+ ret = phy_power_on(phy);
+ if (ret == -EOPNOTSUPP) {
+ /* Skip initializatin of XHCI PHY when it is unsupported by firmware */
+ dev_warn(dev, "PHY unsupported by firmware\n");
+ xhci->quirks |= XHCI_SKIP_PHY_INIT;
+ }
+ if (ret)
+ goto phy_exit;
+
+ phy_power_off(phy);
+phy_exit:
+ phy_exit(phy);
+phy_put:
+ of_phy_put(phy);
+phy_out:
+
+ return 0;
+}
+
int xhci_mvebu_a3700_init_quirk(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
diff --git a/drivers/usb/host/xhci-mvebu.h b/drivers/usb/host/xhci-mvebu.h
index 3be021793cc8..01bf3fcb3eca 100644
--- a/drivers/usb/host/xhci-mvebu.h
+++ b/drivers/usb/host/xhci-mvebu.h
@@ -12,6 +12,7 @@ struct usb_hcd;

#if IS_ENABLED(CONFIG_USB_XHCI_MVEBU)
int xhci_mvebu_mbus_init_quirk(struct usb_hcd *hcd);
+int xhci_mvebu_a3700_plat_setup(struct usb_hcd *hcd);
int xhci_mvebu_a3700_init_quirk(struct usb_hcd *hcd);
#else
static inline int xhci_mvebu_mbus_init_quirk(struct usb_hcd *hcd)
@@ -19,6 +20,11 @@ static inline int xhci_mvebu_mbus_init_quirk(struct usb_hcd *hcd)
return 0;
}

+static inline int xhci_mvebu_a3700_plat_setup(struct usb_hcd *hcd)
+{
+ return 0;
+}
+
static inline int xhci_mvebu_a3700_init_quirk(struct usb_hcd *hcd)
{
return 0;
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 4d34f6005381..c1edcc9b13ce 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -44,6 +44,16 @@ static void xhci_priv_plat_start(struct usb_hcd *hcd)
priv->plat_start(hcd);
}

+static int xhci_priv_plat_setup(struct usb_hcd *hcd)
+{
+ struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
+
+ if (!priv->plat_setup)
+ return 0;
+
+ return priv->plat_setup(hcd);
+}
+
static int xhci_priv_init_quirk(struct usb_hcd *hcd)
{
struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
@@ -111,6 +121,7 @@ static const struct xhci_plat_priv xhci_plat_marvell_armada = {
};

static const struct xhci_plat_priv xhci_plat_marvell_armada3700 = {
+ .plat_setup = xhci_mvebu_a3700_plat_setup,
.init_quirk = xhci_mvebu_a3700_init_quirk,
};

@@ -330,7 +341,14 @@ static int xhci_plat_probe(struct platform_device *pdev)

hcd->tpl_support = of_usb_host_tpl_support(sysdev->of_node);
xhci->shared_hcd->tpl_support = hcd->tpl_support;
- if (priv && (priv->quirks & XHCI_SKIP_PHY_INIT))
+
+ if (priv) {
+ ret = xhci_priv_plat_setup(hcd);
+ if (ret)
+ goto disable_usb_phy;
+ }
+
+ if ((xhci->quirks & XHCI_SKIP_PHY_INIT) || (priv && (priv->quirks & XHCI_SKIP_PHY_INIT)))
hcd->skip_phy_initialization = 1;

if (priv && (priv->quirks & XHCI_SG_TRB_CACHE_SIZE_QUIRK))
diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
index 1fb149d1fbce..561d0b7bce09 100644
--- a/drivers/usb/host/xhci-plat.h
+++ b/drivers/usb/host/xhci-plat.h
@@ -13,6 +13,7 @@
struct xhci_plat_priv {
const char *firmware_name;
unsigned long long quirks;
+ int (*plat_setup)(struct usb_hcd *);
void (*plat_start)(struct usb_hcd *);
int (*init_quirk)(struct usb_hcd *);
int (*suspend_quirk)(struct usb_hcd *);
--
2.20.1